Question

The data type used in Digital Elevation Model (DEM) is .

• A. Raster
• B. Vector
• C. Tabular
• D. Rating

Hint:

DEM represents a continuously varying surface (elevation), and raster grids are designed to store exactly this kind of data.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
A Digital Elevation Model (DEM) is a digital representation of the bare ground surface elevation, without vegetation or buildings. The question asks which GIS data model, raster or vector or something else, is used to store and represent a DEM.

Step 2: Key Formula or Approach:
In GIS, spatial data is stored in one of two basic models. A raster model divides the study area into a regular grid of equal-sized cells (pixels), where each cell holds one value, ideal for continuously varying surfaces like elevation, temperature or rainfall. A vector model instead stores discrete features as points, lines, or polygons with defined boundaries, which suits discrete objects like roads, plots, or buildings.

Step 3: Detailed Explanation:
Elevation is a continuous surface, it has a value everywhere across the terrain, changing smoothly from one point to the next, with no natural sharp edges. This is exactly the kind of data a grid of cells (raster) is built to represent, since each grid cell simply stores the elevation value at that location, and the whole surface is reconstructed by the grid together.
Option (B), Vector, is wrong because the vector data model stores discrete features with defined boundaries, which does not suit a continuously changing surface like elevation.
Option (C), Tabular, is wrong because a plain table of numbers carries no spatial arrangement information, so it cannot describe a 2D surface on its own.
Option (D), Rating, is not a GIS data model at all, it is a scoring or ranking scheme, unrelated to how surface data is structured.

Step 4: Final Answer:
DEM stores elevation as a grid of cell values, so its data type is Raster, option (A).